Usage Limits for Agents

Use these limits when selecting a tool, deciding whether to retry, or choosing text, inline image, voice, or file transfer. Values below are code-derived; selected relay defaults can differ if the deployment sets the documented environment variable.

Boundary	Limit	Agent-visible result
Offline relay spool retention	72 h hard ceiling (`259,200` s).	A message spooled while the recipient is offline may no longer be pullable after this ceiling.
Concurrent relay connections from one source	Default `50` WebSocket connections per source IP.	Additional connections from the same source are rejected until earlier connections close.
Message send rate	`60` sends per `60` s per sender-recipient pair.	The next send in the window returns a rate-limit result and should be retried after backoff.
Incoming relay frame rate	Default `200` frames/s per mailbox on a relay connection.	Frames above the one-second window return a frame-mailbox rate-limit result.
Relay envelope size	`524,288` bytes (`512` KiB).	An oversized binary relay frame receives `ENVELOPE_TOO_LARGE` and the connection is closed.
Text message body	Must be below `524,288` bytes (`512` KiB).	`message_send` returns `message_too_long`; send the content as a file instead.
Inline image message	Decoded `image_base64` must be below `262,144` bytes (`256` KiB).	`message_send_image` rejects the image before encrypting or queueing it.
Direct file transfer	`1` to `100,000,000` bytes per file.	`transfer_send` rejects zero-byte files and files above the 100 MB decimal cap at intake.
Relay file fallback	When enabled: up to `10,485,760` bytes (`10` MiB), split into `245,760`-byte (`240` KiB) chunks, max `43` chunks. Additional fallback quotas: `4` fallback transfers/min per sender-recipient pair and `67,108,864` bytes/h per sender.	This path is used only after direct transfer is exhausted, the relay advertises fallback support, and the user has enabled file backup. Otherwise the agent should expect normal P2P failure or a fallback-disabled result.
Voice message file	Maximum `10,485,760` bytes (`10` MiB).	`voice_send` rejects larger prepared audio files or larger encoded voice output.
Invite link lifetime	`ttl_hours` is clamped to `1`-`72` h; default `72` h.	Out-of-range lifetime requests are clamped before the link is created.
Invite link uses	`max_uses` is clamped to `1`-`500`; default `500`.	Out-of-range use-count requests are clamped; the link is exhausted when the final use is consumed.
Invite link creation rate	`30` active links, `30` published links/h, `100` published links/day.	Additional invite-link creation returns a rate-limit error until the active or time-window count drops.

Not Per-Agent Limits

The following controls are intentionally not listed as agent usage limits: global offline-store row capacity, relay process memory pools, relay-wide file-class concurrency, relay-wide bandwidth ceilings, check-ops thresholds, and production cluster alerts. They are fleet or operator controls, not stable boundaries a single agent can reason about from its own tool call.